The Aneto, with its imposing 3,404 metres, is the highest mountain in the Pyrenees and the second highest peak in Spain. Located in the Posets-Maladeta Natural Park, in the province of Huesca, this mountain is not only a challenge for mountaineers with steep and exposed ascent areas such as the Mahoma Pass, but also a symbol of nature at its purest.

Aneto is a peak that was formed approximately 50 million years ago during the Alpine orogeny, a period of intense tectonic activity that led to the formation of many of Europe’s great mountain ranges. This geological process involved the collision of the Iberian and Eurasian tectonic plates, which led to the rise of the Pyrenees.

The geological structure of Aneto is composed mainly of granite, an igneous rock that solidified from deep magma and was subsequently exposed by erosion and tectonic uplift. Aneto is not alone in its grandeur; it is surrounded by other imposing peaks that form part of the Maladeta massif, such as Pico Maldito (3,350 metres), Pico del Medio (3,346 metres) and Pico de Coronas (3,293 metres). These peaks, together with the Aneto, form a spectacular high mountain landscape, characterised by glaciers, steep ridges and deep glacial moraines, which offer an impressive view of the geological processes that have shaped this region over millions of years.

The first ascent of Aneto

The history of Aneto is full of explorations and adventures that have left an indelible mark on mountaineering. The first documented ascent of Aneto was made on 20 July 1842 by the French geologist and botanist Louis-Philippe Reinaga, accompanied by Pierre Barrau, Bernard Arrazau, Jean Sors and Pierre Sanio. It is unfair not to mention the local mountaineers who guided the French expedition to the summit of the highest peak in the Pyrenees. Without them the milestone of the first documented ascent of Aneto would probably not have been possible, but their names are not known. This expedition undoubtedly marked the beginning of a fascination with the highest peak in the Pyrenees.

Throughout the 19th and early 20th centuries, Mount Aneto became a popular destination for European mountaineers. The construction of refuges and the improvement of roads made access to the mountain easier, attracting a growing number of mountaineers. It is worth mentioning the construction of the famous La Renclusa hut. It was founded in 1916 and has played a crucial role in the history of mountaineering on the Aneto. This refuge has served as a base for countless ascents and scientific expeditions, especially in the field of geology and climatology. The Aneto glacier, the largest in the Pyrenees, is a natural laboratory for the study of the effects of climate change and the dynamics of glaciers…

Route to Aneto Peak

For those seeking to conquer Mount Aneto, the most popular route is the one that starts from the Renclusa Refuge. This route from the Besurta, although demanding, offers impressive views and an unforgettable experience. The route, which crosses ancient glaciers and steep slopes, requires good physical condition and adequate equipment, including crampons and ice axes. There are also other options for climbing Aneto, such as the one that starts at Plan de Senarta and passes through Refugio de Coronas. Finally, from the Estós refuge and via Vallibierna, you can also climb Aneto.

Important: In order to preserve the natural areas, access to the Posets Maladeta Natural Park with a private vehicle is prohibited from the end of June to mid-September. Access is only possible on foot or by bus (AVANZA company). Tickets must be bought directly from the driver and animals must be carried in a carrier.

Route from La Besurta and La Renclusa Refuge

This is the most popular route and is considered the classic way to climb Aneto. It starts at La Besurta, from where you ascend to the Renclusa Refuge (2,140 m).

Route:

La Besurta – Renclusa Hut: A walk of approximately 45 minutes to 1 hour.
Renclusa Refuge – Upper Portillón: You climb along a well-marked path that can be covered in snow, especially at the beginning of the season.
Aneto Glacier: From Portillón Superior, you cross the glacier, where you need to use crampons and ice axe.
Mohammed Pass: The last section before the summit is a narrow and exposed ridge known as the Mohammed Pass. This famous section is a 25 metre long and 50 cm wide ridge made up of boulders. It is not complex but requires calm and careful movement. On both sides the drop is deadly.

Duration: 8 to 10 hours one way: Between 8 and 10 hours round trip from the refuge.

Difficulty: High. Requires good physical condition, experience in high mountains and suitable equipment.


Route from the Coronas Valley

This route is less popular than La Besurta and La Renclusa, but offers an equally spectacular ascent. It starts at Plan de Senarta, from where you follow a path to Refugio de Coronas and reach the Aneto glacier.

Route:

Plan de Senarta – Refugio de Coronas: Approximately 2 hours of walking.
Refugio de Coronas – Ibones de Coronas: From the refuge, continue to the Ibones (lakes) of Coronas.
Coronas Glacier: We ascend the glacier until we reach the Collado de Coronas.
Mahoma Pass: As with the Renclusa route, you cross the Mahoma Pass before reaching the summit.

Duration: Between 10 and 12 hours round trip from Plan de Senarta.

Difficulty: High. Requires experience in high mountains and suitable equipment.


Route from Refugio de Estós

This is one of the longest and least travelled routes to Aneto, starting from the Refugio de Estós, located in the valley of the same name. It offers a more solitary and demanding route.

Route:

Refugio de Estós – Collado de la Plana: A long ascent that may include stretches of light climbing.
Collado de la Plana – Aneto Glacier: It descends slightly to the glacier and crosses it in the direction of the Collado de Coronas.
Paso de Mahoma: The final ridge before the summit.

Duration: Between 12 and 14 hours round trip from the refuge.

Difficulty: Very high. Requires excellent physical condition, experience in high mountains and g


Route from the Vallibierna Refuge

This route is known for its scenic beauty and starts at the Vallibierna Hut. It is a less frequented alternative and offers spectacular views throughout the ascent.

Route:

Vallibierna Refuge – Llosás Lake: Follow the path to Llosás Lake.
Estany de Llosás – Collado de Llosás: A demanding ascent to the pass.
Glaciar de Aneto: From the col, you cross the glacier to the Mahoma Pass.

Duration: Between 10 and 12 hours round trip from the refuge.

Difficulty: High. Requires experience and suitable equipment.


Flora of Aneto

The environment of Mount Aneto is rich in biodiversity. On its slopes you can find endemic species of flora such as the Edelweiss and the Queen of the Alps. This unique ecosystem is one of the reasons why the Posets-Maladeta Natural Park is a protected area. Hikers and mountaineers will see that, as you ascend the slopes of the Aneto, the vegetation changes considerably, going from coniferous forests to alpine tundra. The alpine vegetation of the Aneto is particularly rich in perennial and cushion plants, which are adapted to withstand the cold, strong winds and intense solar radiation.

Emblematic species of the Aneto

Among the most emblematic species of the Aneto flora, the following stand out:

Edelweiss (Leontopodium alpinum): This iconic symbol of the European mountains is known for its beauty and resistance. Its white, woolly flowers are a rare and protected spectacle. If you find Edelweiss on the Aneto or any other mountain, photograph it as often as you like but don’t touch it, let alone pluck it as it is in danger of extinction.
Saxifrage (Saxifraga): Saxifraga are small plants that grow in the crevices of rocks. Their tiny flowers of various colours add a touch of beauty to rocky areas.
Gentian (Gentiana acaulis): The short-stemmed gentian produces intense blue flowers that are a real visual delight in alpine meadows.
Eritrichium nanum: Known as the “Queen of the Alps”, it is found at the highest altitudes, noted for its small blue flowers. It grows in rocky, acid-dominated environments and is often found in areas where glaciers used to be.
Forests and meadows

In the lower areas of the Aneto, mountaineers will notice that forests of black pine (Pinus uncinata) and fir (Abies alba) predominate. These forests provide shelter and food for a variety of local fauna. As one ascends, the forests change into alpine and subalpine meadows, where plants adapted to poor soils and adverse climatic conditions grow.

Adaptations to the climate

The flora of the Aneto has developed unique adaptations to survive in a climate characterised by low temperatures, strong winds and rocky, nutrient-poor soil. Some of these adaptations include:

Small, durable leaves: reduce water loss and protect against wind.
Deep roots: Allow plants to access water and nutrients in the subsoil.
Cushion growth: Minimises wind damage and conserves heat.

The flora of the Aneto is a natural treasure that needs to be protected. Human activities, such as tourism and climate change, can negatively affect these delicate plants. It is crucial to encourage sustainable and environmentally friendly practices to ensure the preservation of these unique species.

Fauna of the Aneto: wildlife at high altitude

The Aneto is not only home to a rich variety of flora, but also to a diverse fauna that has found ingenious ways to adapt to the harsh conditions of the high mountain. The fauna of the Aneto is a crucial component of the ecosystem of the Posets-Maladeta Natural Park, contributing to its biodiversity and ecological balance. If you go to the Aneto in winter, you are likely to come across animal tracks in the snow and you will be able to recognise which animal they are with our simple guide.

High mountain mammals

The fauna of the Aneto includes several mammals that have adapted to living at high altitudes:

Sarry (Rupicapra pyrenaica): also known as chamois, the sarry is one of the most emblematic inhabitants of the Aneto. This agile herbivore is perfectly adapted to steep terrain and can be seen skilfully leaping between rocks. Its thick fur protects it from the extreme cold. Sarrios are spectacular animals that are capable of leaps of up to 6 metres in length and 2 metres in height.
Alpine marmot (Marmota marmota): Marmots are robust rodents that live in colonies and take refuge in underground burrows. They are known for their hibernation behaviour in which they spend six months with their heart rate in brachycardia of only 5 beats per minute. Groundhogs defend themselves with a group tactic. When a groundhog is spotted, it will give the alarm to its companions with a high-pitched sound and they will all go into the burrow, which is interconnected by tunnels that can be up to 20 metres long and three metres deep.
Red fox (Vulpes vulpes): Although more common at medium altitudes, foxes can also be found in the mountainous areas of the Aneto, where they hunt small mammals and birds. This stealthy hunter is a spectacle to watch hunting in the different types of snow. Thanks to its acute senses, it detects rodents under the snow and jumps vertically to pierce the snow cover with its snout and catch the rodent in its jaws.

Birds of prey and mountain birds

Flying overhead as we ascend the Aneto, we are likely to see some of the birds endemic to the area, which undoubtedly add a majestic and vibrant component to the landscape:

Bearded vulture (Gypaetus barbatus): This impressive vulture is known for its unique diet that includes bones. Bearded vultures break bones by dropping them from great heights to access bone marrow.
Golden Eagle (Aquila chrysaetos): One of Europe’s largest and most powerful raptors, the golden eagle can be seen soaring over the mountains in search of prey. Golden eagles have extraordinary vision, about 8 times sharper than that of humans. They can detect a moving hare from a distance of almost 2 kilometres, making them extremely effective hunters.
Alpine Accentor (Prunella collaris): This small bird spends most of the year at high altitudes, adapting to cold winters thanks to its varied diet including insects and seeds. It is a bird known for its unusual social behaviour for a mountain bird. During the breeding season, these birds may form “helping groups”, where several individuals collaborate in feeding the chicks. This behaviour undoubtedly increases the survival rate of the Alpine Accentor.

Reptiles, amphibians and invertebrates at Aneto

Although less visible, reptiles, amphibians and invertebrates are also an integral part of the Aneto ecosystem, each uniquely adapted to the harsh high mountain conditions. Among the reptiles, the Pyrenean lizard (Iberolacerta bonnali) stands out as a species endemic to the Pyrenees. This lizard is found in rocky and sunny areas, adapting perfectly to the fluctuations in temperature in the mountains.

In high mountain aquatic environments, the Pyrenean newt (Calotriton asper) is a common inhabitant. This amphibian inhabits streams and lakes, with a rough skin and brown colouring that allows it to camouflage itself effectively in its aquatic environment, thus protecting itself from predators.

The invertebrate life of the Aneto is equally fascinating and diverse. The Apollo butterfly (Parnassius apollo), known for its great beauty, is common in the alpine meadows. The presence of this butterfly is an indicator of the health of the ecosystem, as it is sensitive to environmental changes. On the other hand, the alpine beetle (Carabus auronitens), an effective terrestrial predator, is found in the cooler, wetter areas of the mountains. This beetle plays a crucial role in controlling populations of small invertebrates, contributing to the balance of the Aneto ecosystem.

Accommodation and camping at Aneto

For mountain and ski lovers, the Aneto and its surroundings offer various accommodation and camping options, adapted to different needs and preferences. From cosy mountain refuges to well-equipped campsites, visitors can enjoy a comfortable stay close to nature.

Mountain Refuges

If you want to do mountain routes, you may decide to stay overnight in a mountain hut. They are a good option to save weight in your backpack, keep you warm and dry in case of rainfall. In addition, you can usually hire mountain guides or at least get tips and advice from experienced local mountaineers. Finally, the fraternal and relaxed atmosphere of the refuges means that with a bit of luck, you will leave with new friends. They used to be very cheap, but the passion for mountaineering has meant that the cost is constantly increasing and booking a place is becoming more and more complex.

Of course, if you want to climb the Aneto, the best refuge to spend the night is the Renclusa Refuge. It is located at an altitude of 2,140 metres and is the most common starting point for ascents of the Aneto. Founded in 1916, it offers basic but comfortable accommodation, ideal for mountaineers and hikers. The refuge has beds, blankets and offers meals, showers and equipment storage. It can be reached on foot from La Besurta in about 1 hour. This place is perfect for meeting other adventurers and sharing experiences.

In the Coronas Valley, the Refugio de Coronas is less frequented but equally beautiful. It offers a spectacular ascent and a quieter experience. With bunk accommodation, kitchen and basic services, it is ideal for mountaineers seeking a more serene environment. From Plan de Senarta, it is an approximate 2-hour walk.

Refugio de Estós, located in the valley of the same name, offers a longer and more challenging route to Aneto. It is a large refuge, with capacity for many visitors and has bunk beds, meals, showers and a cosy atmosphere. It can be reached on foot from the Estós Valley in about 3 hours.

In the Vallibierna Valley, the Vallibierna Refuge offers a less crowded option with spectacular views during the ascent to Aneto. It provides basic accommodation and is a good starting point for quieter routes. It is accessed from the Plan de Senarta with a walk of approximately 2 hours.

Camping at Aneto

Camping Aneto, located in the Benasque Valley, is a popular choice due to its proximity to Aneto and the services it offers. It is ideal for families and groups of friends looking for a stay closer to nature but with modern comforts. The campsite has pitches for tents, caravans and motorhomes, as well as bungalows. It offers toilets, showers, restaurant, swimming pool and recreational activities. From the campsite, you can do various activities such as hiking, cycling and organised excursions to the mountains.

Another campsite in the Benasque Valley is Camping Ixeia, known for its peaceful atmosphere and natural surroundings. It offers pitches and bungalows, with toilets, showers, barbecue area and a small supermarket. It is an excellent starting point for hiking and mountaineering routes in the Pyrenees.

Accommodation in Benasque

For those who prefer more comfort, the nearby village of Benasque offers a wide range of accommodation. During the winter, these accommodations are very popular with the skiing public who come to the ski resort of Cerler and are difficult to book, but during the rest of the year it is usually easier. For example, in Benasque we recommend the Sommos Hotel Aneto. It is a four star hotel located in the centre of Benasque and is ideal for those looking for comfort as well as high quality services. It offers comfortable rooms, a restaurant and organised activities. It is one of the few hotels in the area that offers a swimming pool and spa.

Hotel Ciria, a family hotel with a cosy atmosphere, also located in Benasque, offers comfortable rooms, a restaurant with local cuisine and facilities for mountain activities. On the other hand, it is worth mentioning the Hostal Parque Natural. It is a more economical but equally comfortable hostel for mountaineers and hikers. It offers basic but comfortable rooms, breakfast included and friendly staff willing to help with information on routes and activities.

Traditional gastronomy and drinks in the Aneto area

A visit to the region would not be complete without sampling the local gastronomy. A typical dish that cannot be missing from the meal is the Aneto broth. It is a nutritious soup perfect for replenishing energy after a long day in the mountains. The Aneto broth is prepared with veal, ham bones, fresh vegetables and pulses, and is known for its rich flavour and revitalising properties. This broth was the favourite dish of shepherds and mountain people, who considered it essential to keep them strong during the Pyrenean winters.

Another must-try dish is chiretas, similar to Scottish haggis. They are prepared with lamb tripe stuffed with rice, lamb meat, bacon and spices, slowly cooked until the flavours blend perfectly. This dish is very popular during festivities and family gatherings, symbolising the rich gastronomic heritage of the region.

Cochifrito is a meat lover’s delight, made with lamb or pork cut into small pieces and fried until crispy. It is served with potatoes and peppers, and each family has its own special version, making every bite unique.

We can’t forget the potatoes a la importancia, a simple but very tasty dish. It consists of battered and fried potatoes, then cooked in a broth with garlic and parsley. Although humble, this dish is highly appreciated for its flavour and texture, showcasing the culinary ingenuity of the region.

If you want to take some gastronomic souvenirs home with you, the region is also famous for its artisan cheeses, especially Benasque cheese, known for its robust flavour and creamy texture. These cheeses are made using traditional methods handed down from generation to generation, thus preserving the authenticity and flavour of yesteryear. And on the other hand, you will find a wide range of sausages, such as longaniza sausage and mountain chorizo. Cured and smoked following traditional techniques, these products have intense flavours and are perfect to enjoy with fresh bread and a good local Somontano wine.

For those with a sweet tooth, crespillos are a traditional dessert made with borage leaves dipped in a sweet batter and fried, sprinkled with sugar. This sweet is typically prepared during Easter and is very popular at local festivals.

Pastillo de calabaza is another delicacy, a kind of sweet pastry filled with candied pumpkin. It is especially popular in autumn, when pumpkin is in season, and adds a sweet touch to family celebrations.

After dessert, we cannot forget the sloe liqueur, also known as pacharán. This liqueur is made by macerating sloes in aniseed, resulting in a sweet and aromatic drink, ideal to enjoy after a good meal. In the Aneto region, pacharán has a special flavour thanks to the quality of the local sloes.

Tips and recommendations for the Aneto ascent

For those planning to climb Aneto, it is crucial to be well prepared. In your backpack you should not lack energetic and easy to carry food, such as nuts, energy bars, dried fruits and nuts, as well as enough water, at least 2-3 litres per person. Here is an article on what to pack in your ski backpack which is quite comprehensive and can be quite compatible with what you need on a mountain ascent. Consider carrying water purification tablets or a filter in case you need more. Apart from nutrition and hydration, here are some tips for climbing the Aneto:

Physical preparation: Do endurance and strength training beforehand. Get your body used to ascending and climbing, if possible at altitude. If you are planning to do the great Aneto-Posets trail (18-21 July 2024), your physical preparation should be even more specific.
Adequate equipment: Make sure you wear appropriate clothing and footwear, as well as climbing equipment. A significant part of the ascent to the summit of Aneto is on snow or ice, depending on the state of the glacier and the time of year. You must carry and know how to progress with ice axe and crampons. Finally, it is highly recommended to wear a helmet. If you are going to climb the Aneto in winter, you will probably need to do skimo or ski touring from certain altitudes.
Professional Guide: Consider the possibility of hiring an experienced mountain guide. If you don’t have a lot of experience in the mountains, consider hiring a professional guide. A guide will provide additional safety, knowledge of the route and assistance in difficult situations. Here are some useful telephone numbers for a qualified guide.

  • Benasque Guides: +34 974 551 110
  • Benasque Mountains: +34 609 442 618
  • Aneto Guides: +34 696 349 255

Weather: Check the weather conditions before your ascent.
Safety: Always inform someone of your itinerary and estimated time of return. Take a first aid kit, thermal blanket, whistle and head torch with spare batteries. Of course, don’t run out of battery on your mobile phone.

The general emergency number in Spain is 112.